Lung tissue fluid homeostasis is regulated by endothelial permeability to albumin and liquid such that disrupfion of the endothelial barrier leads to pulmonary edema. We propose to address the potentially important and novel relafionship between endothelial caveolin-1, the signaling protein of caveolae, and adherens juncfions (AJs), structures known to regulate permeability of the junctions. We posit that cross-talk between caveolae and AJs, which up to now have been studied independenfiy, may be of fundamental importance in regulafing AJ permeability. The focus of